[deliverable/linux.git] / drivers / staging / echo / oslec.h

/*
 *  OSLEC - A line echo canceller.  This code is being developed
 *          against and partially complies with G168. Using code from SpanDSP
 *
 * Written by Steve Underwood <steveu@coppice.org>
 *         and David Rowe <david_at_rowetel_dot_com>
 *
 * Copyright (C) 2001 Steve Underwood and 2007-2008 David Rowe
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#ifndef __OSLEC_H
#define __OSLEC_H

/* TODO: document interface */

/* Mask bits for the adaption mode */
#define ECHO_CAN_USE_ADAPTION	0x01
#define ECHO_CAN_USE_NLP	0x02
#define ECHO_CAN_USE_CNG	0x04
#define ECHO_CAN_USE_CLIP	0x08
#define ECHO_CAN_USE_TX_HPF	0x10
#define ECHO_CAN_USE_RX_HPF	0x20
#define ECHO_CAN_DISABLE	0x40

/*!
    G.168 echo canceller descriptor. This defines the working state for a line
    echo canceller.
*/
struct oslec_state;

/*! Create a voice echo canceller context.
    \param len The length of the canceller, in samples.
    \return The new canceller context, or NULL if the canceller could not be created.
*/
struct oslec_state *oslec_create(int len, int adaption_mode);

/*! Free a voice echo canceller context.
    \param ec The echo canceller context.
*/
void oslec_free(struct oslec_state *ec);

/*! Flush (reinitialise) a voice echo canceller context.
    \param ec The echo canceller context.
*/
void oslec_flush(struct oslec_state *ec);

/*! Set the adaption mode of a voice echo canceller context.
    \param ec The echo canceller context.
    \param adapt The mode.
*/
void oslec_adaption_mode(struct oslec_state *ec, int adaption_mode);

void oslec_snapshot(struct oslec_state *ec);

/*! Process a sample through a voice echo canceller.
    \param ec The echo canceller context.
    \param tx The transmitted audio sample.
    \param rx The received audio sample.
    \return The clean (echo cancelled) received sample.
*/
int16_t oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx);

/*! Process to high pass filter the tx signal.
    \param ec The echo canceller context.
    \param tx The transmitted auio sample.
    \return The HP filtered transmit sample, send this to your D/A.
*/
int16_t oslec_hpf_tx(struct oslec_state *ec, int16_t tx);

#endif	/* __OSLEC_H */
Commit	Line	Data
17f8c114 TC	1	/*
	2	* OSLEC - A line echo canceller. This code is being developed
	3	* against and partially complies with G168. Using code from SpanDSP
	4	*
	5	* Written by Steve Underwood <steveu@coppice.org>
	6	* and David Rowe <david_at_rowetel_dot_com>
	7	*
	8	* Copyright (C) 2001 Steve Underwood and 2007-2008 David Rowe
	9	*
	10	* All rights reserved.
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2, as
	14	* published by the Free Software Foundation.
	15	*
	16	* This program is distributed in the hope that it will be useful,
	17	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	19	* GNU General Public License for more details.
	20	*
	21	* You should have received a copy of the GNU General Public License
	22	* along with this program; if not, write to the Free Software
	23	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	24	*
	25	*/
	26
	27	#ifndef __OSLEC_H
	28	#define __OSLEC_H
	29
	30	/* TODO: document interface */
	31
	32	/* Mask bits for the adaption mode */
	33	#define ECHO_CAN_USE_ADAPTION 0x01
	34	#define ECHO_CAN_USE_NLP 0x02
	35	#define ECHO_CAN_USE_CNG 0x04
	36	#define ECHO_CAN_USE_CLIP 0x08
	37	#define ECHO_CAN_USE_TX_HPF 0x10
	38	#define ECHO_CAN_USE_RX_HPF 0x20
	39	#define ECHO_CAN_DISABLE 0x40
	40
	41	/*!
	42	G.168 echo canceller descriptor. This defines the working state for a line
	43	echo canceller.
	44	*/
9d8f2d5d	45	struct oslec_state;
17f8c114 TC	46
	47	/*! Create a voice echo canceller context.
	48	\param len The length of the canceller, in samples.
	49	\return The new canceller context, or NULL if the canceller could not be created.
	50	*/
9d8f2d5d	51	struct oslec_state *oslec_create(int len, int adaption_mode);
17f8c114 TC	52
	53	/*! Free a voice echo canceller context.
	54	\param ec The echo canceller context.
	55	*/
9d8f2d5d	56	void oslec_free(struct oslec_state *ec);
17f8c114 TC	57
	58	/*! Flush (reinitialise) a voice echo canceller context.
	59	\param ec The echo canceller context.
	60	*/
9d8f2d5d	61	void oslec_flush(struct oslec_state *ec);
17f8c114 TC	62
	63	/*! Set the adaption mode of a voice echo canceller context.
	64	\param ec The echo canceller context.
	65	\param adapt The mode.
	66	*/
9d8f2d5d	67	void oslec_adaption_mode(struct oslec_state *ec, int adaption_mode);
17f8c114	68
9d8f2d5d	69	void oslec_snapshot(struct oslec_state *ec);
17f8c114 TC	70
	71	/*! Process a sample through a voice echo canceller.
	72	\param ec The echo canceller context.
	73	\param tx The transmitted audio sample.
	74	\param rx The received audio sample.
	75	\return The clean (echo cancelled) received sample.
	76	*/
9d8f2d5d	77	int16_t oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx);
17f8c114 TC	78
	79	/*! Process to high pass filter the tx signal.
	80	\param ec The echo canceller context.
	81	\param tx The transmitted auio sample.
	82	\return The HP filtered transmit sample, send this to your D/A.
	83	*/
9d8f2d5d	84	int16_t oslec_hpf_tx(struct oslec_state *ec, int16_t tx);
17f8c114 TC	85
17f8c114 TC	86	#endif /* __OSLEC_H */